How to Start Planning a Home Addition: 6-Step Guide

an addition being built as part of a home improvement project

Are you thinking of making house extensions on your existing property? Before you call the local builders, there are steps you must take to prepare for a home addition. Firstly, planning a home addition properly ensures you don’t get scammed by an unreliable builder. Secondly, planning a home addition the right way prevents code violations, fines, unnecessary expenses, and a lot of stress!

Keep reading to learn how to start planning a home addition to avoid stress, fines, and unnecessary expenditure.

How to Start Planning a Home Addition

First and foremost, you need to have a clear idea of your existing house. When it comes to home improvement, you need to consider these in your planning permission: 

1. Decide Your Criteria

Considering the three terms above, you should ensure the property meets your preferences from the following criteria:

2. Set a Budget

a woman real estate agent on a phone at a desk

Even if you’re bent on having a single-story extension, it will all be for naught if you don’t have the money for it. You need to have at least $100,000 at hand before the project begins. You also need an additional 15% fund to cover emergency expenses as the project progresses. 

Read our guide on how to fund home renovations to learn more.

3. Hire a Professional Builder & Project Manager

Home extensions are no DIY thing. You need to work with various professionals from the get-go. To start, you need to obtain permission for the construction. 

Next, you need an architect and building designer to draw detailed plans. They can help you choose the right extension from the options below. You also need to hire your main contractor, quantity surveyor, structural engineer, and interior designer, among many other experts. 

For best results, make sure to ask for at least three quotes. That way, you can compare everything against your set budget. 

4. Choose the Type of Home Addition

a row of family properties in america

There are various types of home additions you can choose to proceed with. Which one works best for you depends on the property size, space required, local building codes, and personal preferences. Here are the main types of home additions.

Side or Back House Extension

As the name suggests, this type of additional means expanding the side or back portion of your home. While a front extension is always possible, your local council may not permit it. That’s why it’s essential to work with a professional project manager, for there may be rulings that may restrict your plans.

New Floor

Having an additional floor is the dream. However, it’s not always feasible because of the additional costs. This also requires a lot of requirements, such as a study, which can take as long as six months.

Basement Excavation

This home extension is a favorite among those who want to add to their existing rooms. With a basement excavation, you can have a home office, cinema, and even a basement bedroom.

Cantilever Additions

The cantilever is a self-supporting structure similar to a balcony. Joists support it, so the system remains inside the original building itself. Compared to other house extension projects, it doesn’t provide additional space.

Attic Space Project

The attic is not always a suitable living space. With the help of a professional designer, you may transform this space into an additional bedroom.

Veranda or Sunroom

While they don’t always equal more space, they can give your home an additional area for lounging and whatnot.

Attached/Detached Garage

Whether it’s for an additional car or something else, a garage is an excellent addition to a terraced house. 

5. Select Materials

You want your chosen builder to use quality materials. That’s why it’s essential to set a budget to reconcile your needs with your wants. Here are some of the areas that will require quality materials:

6. Check Local Building Codes

Before you get started with any of the projects above, you need to check the building notice and rules in the area. That’s why it’s good to hire professionals in project management. They can address all the issues because they’re experts on all the processes involved.

For one, they can help you apply for the permits in advance. The lack of certain documents can lead to delays, and they’ll make sure your project won’t be hampered because of that. They can also help you save on fees, for you need to pay every time you file for permits. 


Getting your house extended is often costly and challenging. But, as long as you follow this essential guide, you can cover all the bases for your home extension. Remember, it’s important to plan first before speaking to a contractor. While an expert can guide you in the right direction, it’s easy to get caught up in what they say.

A bad contractor can quickly take advantage and suggest unnecessarily high budgets if they suspect you haven’t done your research. That’s why it’s always key to plan first and find a good contractor before planning your renovation project.

Are you deciding whether a home addition is worth it? Or debating whether to renovate vs sell your property? At Brotherly Love Real Estate, we can help. We buy houses fast for cash in Philadelphia, San Diego, and New Jersey. We help investors sell a property quickly and can advise if a property is worth extending before selling to us.

To learn more about what we do, contact us online or give our expert team a call today at (215) 769-9875.